eleven wrote:SpAce wrote:The first thing that jumps out to my eye, even without candidates, is the Unique Rectangle (19)r13c29. We've talked about those before. It solves r3c2, after which it's singles.

Without candidates, i would say, it solves r3c3:

That works too. This is about the easiest possible UR configuration (3/4 cells obviously locked with the UR candidates + digit 9 just as obviously locked in all UR cells) so there are many possibilities to solve it. I tend to use UR Type 1 logic when it's available (i.e. place r3c2 in this case), but just as well you can use UR Type 4 logic and place r3c3, or you could place r1c2 just as easily. All are trivial with or without candidates, if you know what you're doing. UR Type 1 is probably the easiest to grasp, so I'd recommend starting with that if UR concepts are new.

There is also a naked pair in row 5, which - also without candidates - is easier to spot for me than the hidden triple in that row.

It's a good row to practice spotting various locked sets, as it has a degenerate naked quad/hidden quad pairing at the top level. Because it's degenerate, the naked quad contains a naked triple which contains a naked pair (so you get two singles when you break it). Similarly the hidden quad contains the hidden triple you mentioned (as long as 9r5c9 has been eliminated).